The use of cargo compartment covers for closing the cargo bay of a station wagon is known from the prior art. Such cargo compartment covers are constructed in the manner of a roller blind. A winding shaft is rotatably seated in an elongated cassette or housing detachably arranged in the vehicle behind the rear seatback. The winding shaft is biased with the aid of a spring motor in a roll-up direction of the cover sheet, one edge of which is fastened to the winding shaft.
A contour part with a handle is situated at the other edge of the cover sheet. The contour part can be gripped manually and moved by pulling out the cover sheet in the direction toward the tailgate opening. There the contour part is appropriately hooked into a laterally projecting pin. This spring motor holds the cover sheet under tension.
A refinement of such a roll-up cover is known from EP 1084907 A2. The disclosed roll-up cover which automatically goes into a partially open position when the rear door is opened. This is intended to increase the convenience of use. It is normally not necessary to open the cover sheet completely for loading or removing objects from the cargo compartment. A partial opening which extends only far enough to enable unobstructed access is necessary. In the arrangement according to EP 1084907 A2 this is achieved by moving the contour part in the direction towards the roof via guide rails that are inserted into the D-column. For this purpose, guide rail arrangements that have two guide groups are present in the D-columns. A pin of the contour part runs in one of these guide groups, while an actuation member is guided in a buckling-free manner in the other. The pin is connected to the actuating member by a coupling part, which is connected in the first guide groove and in the second guide groove.
For driving the actuating members, a single electric motor is provided which bears an output gear with which the two actuation members, which are constructed as flexible racks with teeth on all sides, are in positive engagement. Due to this arrangement one of the actuating members is relatively short, while the other must also be run over the entire width of the cargo compartment bottom thereby producing a corresponding amount of friction. In addition, the placement of the additional guide that connects the motor to the guide rail on the opposite side of the door is expensive and complicated.
A cargo compartment cover in which the cover sheet need only be moved horizontally is described in DE 19825353 A1. Two guide rails, to which end parts of the contour part are connected and with which they are guided, run along the lateral edges of the cargo bay. Deflection rollers in the form of toothed belt pulleys are provided at the front and rear end in each of the guide rails. An endless toothed belt, whose upward facing operating strand bears a coupling part for the lateral pins of the contour parts, runs around each two pulleys of a guide rail. For each guide rail, the belt pulley situated at the front end of the cargo bay is driven via its own an electric motor. In order to reliably prevent uneven movement of the contoured part in the opening or closing movement, the operation of the two motors is synchronized electrically via of an expensive synchronization circuit. Electrical synchronization is technically difficult, and presumes gear motors that contain additional sensors in order to enable an electrical synchronization.